Antibacterial quaternary ammonium salts and method of preparing the same

ABSTRACT

A novel class of quaternary ammonium salts is described and characterized chemically. Preparation of a prototype of the class is described, and hereinbelow the structure of the product is specified. The letters, such as n1, n2, n3, Z, m, etc., are more fully described in the specification. The antibacterial activity of this class of compounds is demonstrated and their compatibility with phenolic bacteriostats as well as with soap is illustrated. Quaternary ammonium compounds having antibacterial action are known in the art, but have limited activity, particularly with respect to Escherichia Coli and Pseudomonas aeruginosa, also tending toward skin and eye irritation, and also have limited compatibility, if any, with phenolic antimicrobial agents. These and other limitations in said known salts are overcome by the novel compounds contemplated by the present invention.

United States Patent [191 Molnar [451 May 20,- 1975- ANTIBACTERIAL QUATERNARY AMMONIUM SALTS AND METHOD OF PREPARING THE SAME [21] Appl. No.: 223,308

[52] US. Cl. 260/567.6 P; 252/106; 260/584 B;

424/329; 260/50l.19 [51] Int. Cl. C07c 91/02 [58] Field of Search 260/567.6 P, 584 B, 501.19

[56] References Cited UNITED STATES PATENTS 2,683,147 7/1954 Airod 260/567.6 P

Primary ExaminerDonald G. Daus Assistant Examiner-W. B. Springer Attorney, Agent, or FirmW. Lee Helms [57] ABSTRACT A novel class of quaternary ammonium salts is described and characterized chemically. Preparation of a prototype of the class is described, and hereinbelow the structure of the product is specified. The letters, such as n n n Z, m, etc., are more fully described in the specification. The antibacterial activity of this class of compounds is demonstrated and their compatibility with phenolic bacteriostats as well as with soap is illustrated.

Quaternary ammonium compounds having antibacterial action are known in the art, but have limited activity, particularly with respect to Escherichia Coli and Pseudomonas aeruginosa, also tending toward skin and eye irritation, and also have limited compatibility, if any, with phenolic antimicrobial agents. These and other limitations in said known salts are overcome by the novel compounds contemplated by the present invention.

6 Claims, No Drawings ANTIBACTERIAL QUATERNARY AMMONIUM SALTS AND METHOD OF PREPARING THE SAME In accordance with this invention, the particular group of quaternary ammonium compounds is characterized by the presence of from three to six free hydroxyl groups, from one to four chlorine or bromine atoms, of two quaternary nitrogens in their cations and by the presence of two ionizable anions. Further characteristics are evident from the general formula:

H C-O (CI-l Z (CH O) n (l-lC-O (Cl-l Z (Cl-I 0) n2- H CO (Cl-l Z (Cl-I 0) n n c-o( n cim CH2 wherein R and R are alkyl groups each containing 1 to 3 carbon atoms,

R is alkyl or alkenyl containing 8 to 18 carbon atoms,

2 is hydrogen or CH X is chlorine or bromine,

A is chosen from the group of chloride, bromide, iodide, paratoluene sulfonate or any other physiologically acceptable anion,

11,, n and n are integers ranging from 1 to 10, and m has the value of 1 or 2.

l on on N Z trative examples are decyl dimethylamine, dodecyl dimethylamine and di-n-propyl octylamine. In connection with the latter reaction, the unexpected observation was made that only the two halides whose positions corresponds to the positions of the primary alcoholic groups in the starting polyols react with the tertiary amines employed. The following example illustrates the sequence of reactions and the chemical operations involved.

10 EXAMPLE I. The intermediate product I is prepared from com- I t/ CH CH 3 CH2-CHCH2 c1-) (IJH 4O) -1 CH CHCH CI l H C 0((3 H 0) 2 CH CHCH C1 Intermediate I As shown, the backbone of the novel quaternary salts is formed by polyols chosen from the group of 3 to 6 polyhydric aliphatic alcohols. Illustrative of this group are glycerol, pentaerytherol and sorbitol. The polyols are condensed with an appropriate 1,2-epoxyalkane, such as ethylene or propylene oxide. The resulting polyethers are next reacted with epichloro or epibromohydrin. Finally, the obtained organic halides are condensed with a tertiary amine containing one higher alkyl or alkenyl or halo-substituted alkyl radical. Illus- I CH CHCH CI n n, n approximately 12+ ll. Mix 309 g( /a mol) of I,

180.5 g mol) dimethyl dodecyl-amine and 600 ml n-butanol.

*Dodecyl in this instance, but not limited thereto, a commercial product containing, for instance, 65% C 25% C and I07: C alkyls may be used as well.

Maintain the reaction mixture at ll5l20C for 18 hours. Then strip off butanol; a viscous fluid is obtained in nearly quantitative yield.

The product thus obtained, and referred to in the following as HQ8, shows on analysis three free hydroxy groups, and three chlorines, one of the latter is not ionized in solution.

Where it, 11 n =12 Obviously any other suitable tertiary amine may be used as a quaternizing agent such as those containing higher alkenyl or halogen-substituted alkyl or alkenyl groups. In place of the methyl groups, may be ethyl or propyl or both ethyl and propyl and be within the scope of this patent disclosure. In addition, the anion may be bromide, iodide, para-toluenesulfonate or any other physiologically acceptable anion.

The quaternary ammonium compounds subjects of the invention, are soluble in water, have very low toxicity, and are safe to the skin under use dilution, and are compatible with phenolic type antibacterial agents, the latter having very low activity, if any, against inhospital occurring disease-producing pseudomonas strains. The present compounds are effective against the latter Gram-negative organism, and against E. coli as well; also against Gram-positive organisms such as Staphylococcus aureus, and against fungi, such as Asper- Results Dilutions of HQ-8 Organism Controls Legend:

A most unexpected and useful finding was that the quaternary is compatible with phenolic disinfectants,

I physiologically suitable for a surgical scrub. However,

by solubilizing the above phenolic germicides with HQ 8, activity is noted against Pseudomonas aeruginosa. Eye or skin irritation is not caused by suitably compounded compositions. Also discovered was the unexpected finding that HQ 8 has the capacity to solubilize in water the above normally-water-insoluble germicides, thus increasing and broadening their antibacterial properties, rendering said composition unexpectedly effective against Pseudononas aeruginosa.

BIOLOGICAL TEST I Test media Nutrient broth (Difco) Innoculum: Bacteria 1% of 24 hr. broth culture.

Fungi 1% of a 10% dilution of a 7 day spore growth.

Letheen Broth (Difco). 48 hours at 37C.

Subculture media: Incubation:

ORGANISMS E. coli Ps. aeruginosa MEC kill MEC kill S. aureus means growth (signifies no antimicrobial activity) means no growth (signifies antimicrobial activity) gillus niger. Pseudomonas aeruginosa is an unusually resistant organism, but HQ 8 as shown below was found 60 very effective.

Minimum Effective Concentration Organism Bactericidal Bacteriostatic Staphylococcus aureus 5 ppm 5 ppm 65 Escherichia coli 22 ppm 19 ppm Pseudomonas aeruginosa 43 ppm 22 ppm Aspergillus niger 37 ppm 37 ppm BIOLOGICAL TEST II The foregoing test formulation showed superiority, I particularly at 30 minutes and 18' hours contact time,

The formulation employed: LAB NO. FO 71-596 2% 3,4,5 tribromosalicylanilide (Temasept, Fine Organics T.M.)

4,2',4' trichloro-Z-hydroxydiphenylether 5 surface active agents, principally anionic in character,

% (of 37%) being partly anionic and partly nonionic.

9% (approximately) other adjuvants Escherichia coli and Pseudomonas aeruginosa when compared with pI-lisoHex (a commercial product containing 3 percent hexachlorophene, a commonly used hospital surgical scrub, chemically 2,2 methylene bis against the important Gram-negative organisms of 47.57 Water I 6 (3,4,6 trichlorophenol) the latter showing no activity Conditions of Test II I Test dilutions: as is 10 gm Sample) 1 against E. coli and negligible or no activity against Ps.

8% solution (w/v cc sample) 0 aemgmosa- I Contact Time: l5 minutes at room temperature (RT) minutes at room temperature 18 hours at 4C S. aureus E. coli P5. aerugiriosa BIOLOGICAL TEST Ill Testorgamsms: This test shows that by tube dilution technique the 5 formula used in Biological Test Ill killed S. aureus, E. Incubation:

24 h t37C I steeping Time; 15 3:3 at c011 at a dilution of at least I230 and Ps. aerugznosa at g gp f ig g fi j i g f 1:15 dilution and inhibited th'e growth of all these or- L f i W amemstfss ganisms at least 1:30, whereas pI-IisoI-Iex gave kill at these dilutions only against S. aureus, and failed to kill The results are tabulated and recorded according to the 20 E. coli and Ps. aeruginosa at 1:5 dilution.

standard test procedure as employed in In Vitro Tests for Measuring Antibacterial Activity of Toilet Soap and I Detergent Bars, Journal of Pharmaceutical Sciences Conditions of Test III: (Tube Dilution Method) I Samples tested same as in Test II. Organisms: S. aureus, E. coli, Ps. aeruginosa treated skin disk is in contact with the bacteriologically Vol. Pg. 827, Vinson et al., author. Dilution media: AATCC Bacteriostasis Broth The contact time definesthe length of time the 25 All dilutions were w/v.

Results of Test III:

' No. 71- 596 I pHisoHex Dilution S.-aureus E. coli Ps. aeru, S. aureus, E. coli Ps. aeru.

MEC kill I MEC kill MEC kill MEC kill MEC kill MEC kill 1-30 r- Control I I BIOLOGICAL TEST 1v Shows the activity of the present compound, as of the Test I formula, in the presence of soap. The slightly bet-' inoculated agar media at room temperature (R.T.) and at 4C. It is to be noted that when antimicrobial substances are strongly substantive to the skin (,this being desirable) it takes longer time (30 minutes vs. 15 minutes) to demonstrate their presence, because of slow diffusion from the skin 'disk into the culture medium, the colder temperature of 4C (refrigerator temperasomewhat in the lower activity against the Gramnegative. Comparison of Tables I and IV is suggested.

0 ter Gram-positivejaction in presence of soap was offset I ,SAMPLE: H s ture) is necessary for long contact time 18 hours I I s Q to prevent the organisms growing in the test media be- Test Medlai Nument Broth Contammg 8 Percent fore diffusion takes place, Ivory p Test II Results: I Ps. Salmonella S. aureus, I E. coli aerugi'npsa choleraesuis (Duplicate results recorded) DIIUFIOIIS MEC kl" I MEC klII MEC klII MEC km (A) Contact time 15 minutes at RT Ps. Sample S. aureus E. coli aeruginosa I000 s00 7l-596 as is 4,4 1,1 l,l 250 f 8% 2,2 0,0 0,0 I 125 *pHisoHex as is I 4,4 0,0 0,0 8% I 4,4 0,0 00 31 (B) Contact time 30 minutes at RT 7l596 as is 4,4 2,2 1,1 I I 8% 4,4 1,1 0,0 f3 1; I i i I 4 0 0,0 I I- 21 Hex as 1?, :8 0,0 Controls I (C) Contact time l8 hours at 4C 7l-596 as is 4,4 4,4 2 2 8% 4,4 3,3 1,1 SAFETY HisoI-Iex as is 4,4 0,0 l,l p 3% 44 0,0 09 A comparative test was done on pI-I1soI-Iex and the 65 surgical scrub formulation as above disclosed to determine possible brain cell damage to rats through dermal application; surgical scrub containing 4 percent of HO 8 and 2% 3,4,5 tribromosalicylanilide (Temasept IV) and 0.5% 4,,2'4, trichloro-Z-hydroxydiphenylether and the pHisol-Ie t scrub containing 3 percent hexachloi'o- A commercial surgical scrub preparation containing 37: hexachlorophene. Ratings:

4 clear, sharply outlined zones excellent activity 3 hazy periphery good activity 2 partial growth fair activity I growth almost equal to surrounding area poor activity 0 i no zone of inhibition no activity I 7 8 phene. Daily application was conducted for 30 days, Eye irritation studies and skin irritation studies after which the rats were sacrificed and the brains fixed showed the disclosed formulation to be safe. in Bouins Solution for microscopic study.* Staining Having described my invention, what is claimed is as and mounting of the tissues were done* by Histological follows: Enterprises, Fort Washington, Penna. l-listopathol. A quaternary ammonium salt of the following genlogical evaluation of the brain tissues was made by eral structure:

OH R l 7 l H C- ()(CH iJHO CH CH CH N R A Z OH l (HO -O(CH /CHO) CH Y CH CH X) OH 1 I H2C-O(CH /CHO) CH CH CH l t- R A- Z 9 2O Donald A. Willigan, D.V.M., Ph.D.** wherein R and R are alkyl groups each having 1 to 3 Method described in The oral and Dennal Toxicity of Hexachlorocarbon atoms phene in Rats", Gaines & Kimbrough, Tenth Annual Meeting of the Soci%t7y ofToxicology, Washington, DC. March 7-ll, l97l.Abstract 3 alkyl or alkenyl contammg 8 to 18 carbon N0. atoms,

Microscopic Evaluation of Rat Brains From Five Experimental Groups, August 24, [971. Donald A. Willigan, D.V.M., PhD. Z hydrogen or CH3,

It was found that Temasept 14 (3,4,5 tri- X chlorine or bromine; bromosalicylanalide) caused no demyelination (spongy A c chosen from the group of chloflde, bromlde, degeneration) of the white matter and fiber tracks (cefhdc, Paratclucnc snlfcnatc any other P y grebrum, cerebellum, and modella oblongata) of the lcauy acceptable anion, brain. pHsiol-lex containing 3 percent hexachloro- 3O "2 and "3 a1'cintcgcrs 1'anging from 1 to 10, and phene (2,2 -methylenebis-3,4,6-trichlorophenyl) used m has the Value of l as a comparative control, under the same conditions, A bactericidal and fungicidal quaternary ammo produced gross microscopic changes in the white matninm Salt according to claim wherein 1 and 2 are ter of the brain.* Microscopic examination of tissue each methyl groups and 3 is a dodccyl psections of the brain also showed the formulation F0 A bactericidal and fungicidal quaternary ammo 71-596 containing 4% HQ8, 2% TBS d 05% 4 2',4' nium salt according to claim 1, wherein R represents trichloro-Z- hydrocydiphenylether, when applied der- 3 mixture of alkyls containing from s t0 w cal'bonsmally for 30 days to rats, failed to show any brain dam- A quaternary ammonium Salt acccrding claim age on any of the test animals, whereas the application 40 Where X is Chlorineof pl-IisoHex containing 3% hexachlorophene exhibited A bactericidal and fungicidal q ernary a'mmO- brain damage on all of the test animals of the control nium salt according to claim wherein h um of tests. n and n ranges from 3 to 40, *Method described in The oral and dermal toxicity of hexachloro- 6. A quaternary ammonium salt according to claim phene in Rats", Gaines & Kimbrough, Tenth Annual Meeting of the Society of Toxicology, Washington, DC. Mar. 71 I, 1971 Abstract Wherem the amons are Selected from the group con- No. 37. sisting of chloride, bromide, or iodide. 

1. A QUATERNARY AMMONIUM SALT OF THE FOLLOWING GENERAL STRUCTURE:
 2. A bactericidal and fungicidal quaternary ammonium salt according to claim 1, wherein R1 and R2 are each methyl groups and R3 is a dodecyl group.
 3. A bactericidal and fungicidal quaternary ammonium salt according to claim 1, wherein R3 represents a mixture of alkyls containing from C8 to C18 carbons.
 4. A quaternary ammonium salt according to claim 1, where X is chlorine.
 5. A bactericidal and fungicidal quaternary ammonium salt according to claim 1, wherein the sum of n, n2 and n3 ranges from 3 to
 40. 6. A quaternary ammonium salt according to claim 1, wherein the anions are selected from the group consisting of chloride, bromide, or iodide. 